Braves vs. Astros injuries reshape Sept. 12–14 series in Houston
Sep, 13 2025
Injuries set the tone for Braves–Astros in mid-September
Nine. That’s how many Atlanta players are on the injured list as the Braves hit Houston for a three-game set from September 12–14, 2025. The Astros aren’t healthy either, and the strain shows most on the mound. This series won’t be decided by star power as much as by who can cover innings, control the running game, and avoid the one bad matchup in the sixth.
Atlanta’s situation is stark. The Braves injured list stretches across every corner of the roster—everyday bats, high-leverage relievers, and young starters. It’s a snapshot of a season that has already slipped away, with the club eliminated from playoff contention and forced to build lineups and rotations from what’s left on the depth chart. Houston’s sheet is shorter, but the timing matters: two elbow issues in September thin out a staff that needs reliability late.
The key storyline is less about who’s playing than who isn’t, and how managers script around those gaps. Expect conservative pitch counts, quick hooks, and a level of matchup micromanaging you usually see in October—only this time it’s about surviving the weekend.
The injury picture and the ripple effects
Let’s start behind the plate. Sean Murphy remains on the 10-day IL with a hip issue. His 2025 line—.199/.300/.409 with 16 homers and 45 RBIs—looks light at first glance, but the power plays, and his defense and game-calling are part of the Braves’ run-prevention backbone. Without him, Atlanta leans on a backup tandem to manage a patched-together pitching staff. That shows up in two places: controlling the running game and steering traffic when pitchers fall behind in counts.
On the 15-day IL, the Braves are missing two arms they counted on to stabilize different parts of a game. Left-hander Aaron Bummer is out with a shoulder injury after logging a 3–2 record, 3.81 ERA, and 8.4 K/9. He’s the kind of sinker-slider reliever who erases rallies with a ground ball and neutralizes lefty thumpers. Without him, those middle-inning, two-on spots become higher risk, and the manager may be forced to ask a righty to navigate a tough lefty pocket.
Daysbel Hernández joined Bummer on the 15-day IL with right shoulder inflammation, backdated to September 9. His 2025 performance—4–3, 3.41 ERA, 8.0 K/9—was quietly efficient in bridge innings. Backdating means he’s out for this series, and Atlanta loses another option for the fifth, sixth, and seventh. That’s where the Braves may now need to go matchup-by-matchup instead of handing an inning to a single reliever.
The 60-day IL is where the long-term pain lives. Grant Holmes (elbow) had a 4–9 record with a 3.99 ERA, and a sturdy 9.6 K/9. The record undersells him; the strikeouts and ERA suggest a swingman who kept Atlanta in games. His absence strips the rotation of a bulk arm who could save a bullpen during a rough week.
Joe Jiménez is also out long-term with a knee problem, and he doesn’t have 2025 numbers on the board. Even if he hadn’t been in peak form, that veteran late-inning presence matters. In September, when every pitch can tilt a bullpen day, not having a familiar high-leverage option forces the manager to mix and match and hope roles stick for a night.
Two developing starters tell the story of “what might have been” for Atlanta. AJ Smith-Shawver is shelved by calf and elbow injuries after a promising line—3–2, 3.86 ERA, 8.5 K/9. He’s the type of arm you build a second-half surge around: misses bats, limits damage, learns on the fly. Take him out of the picture, and the rotation’s ceiling ticks down. That pushes more innings to the bullpen, where the Braves are already thin.
Reynaldo López landed on the shelf with a shoulder problem after some alarming indicators—a 5.40 ERA and just 1.8 strikeouts per nine. That K rate hints at an arm searching for shape or finish on his pitches. Whether it was health or mechanics, losing him reduces the Braves’ options to chase soft contact or soak up lower-leverage frames without fireworks.
Atlanta’s everyday lineup takes its biggest hit at third base. Austin Riley is out with an abdominal injury. He was slashing .260/.309/.428 with 16 homers and 54 RBIs—production that anchors the middle of the order and protects the hitters ahead of him. Without Riley, the Braves lose a right-handed power threat who punishes mistakes and lengthens at-bats. It changes how opponents pitch the heart of the lineup; you’ll see more aggressive fastballs and fewer get-me-over breaking balls when the fear factor is gone.
On the mound, Spencer Schwellenbach’s elbow injury might be the single most painful loss relative to expectation. He’d been one of the club’s steadiest arms—7–4 with a 3.09 ERA and 8.8 K/9—and looked like a set-and-forget rotation piece. Remove that level of performance, and the staffing plan shifts from “who closes the door?” to “who keeps it propped open without the wind knocking it down?” The innings have to come from somewhere, and replacing quality with quantity almost always leads to stress innings.
Stack all of that together and you get the big-picture Braves reality: nine names on the IL, several of them in defining roles, and a team already doing 2026 homework in September. Expect auditions across the diamond—late-inning at-bats for younger hitters, multi-inning looks for fringe relievers, and defensive experiments that give the front office more tape.
Houston’s list is shorter, but the timing is tricky. Spencer Arrighetti remains on the 15-day IL with an elbow issue. The numbers show the ups and downs of his 2025—1–5, 5.35 ERA, 7.9 K/9—but the swing-and-miss is there. Without him, the Astros lose a rotation or tandem option who can strike his way out of traffic. Those are the outings that keep bullpens fresh in a three-game set.
Left-hander Bennett Sousa is also on the 15-day IL with an elbow injury. His specifics aren’t in this report, but the profile matters: a lefty middle reliever lets you tilt matchups in parks like Minute Maid, where a single short porch fly can flip a game. Without Sousa, Houston’s left-on-left lever is lighter, and that can show up in the sixth or seventh when a lefty power bat steps in with men on.
What does that mean on the field? Both managers will lean on the 28-man September roster rules, pairing short starts with multi-inning relievers and asking rookies to carry leverage spots. It’s survival mode, but it’s controlled—more like a series of planned sprints than a frantic scramble.
For Atlanta’s lineup, the absence of Riley reshapes the batting order. You’ll likely see more small-ball variations—hit-and-run tries, steals when the count favors it, and situational swings with two strikes. With Murphy out, the offense loses some right-handed lift, so stringing three hits in an inning could be the path rather than waiting for the three-run homer.
Defensively, catcher play becomes a hinge. Handling a bruised bullpen means knowing when to steal a borderline strike and when to block a breaking ball in the dirt with a runner at third. Houston runs opportunistically. If Atlanta’s catchers can’t slow the game down with sequencing and throws, extra 90 feet will stack up.
On the mound, the Braves’ approach likely trends to “shorter stints, more looks.” Instead of asking a fifth starter to turn a lineup a third time, they’ll team up two or three arms: a soft-contact opener, a slider-heavy righty for the middle, and a high fastball arm for the pocket of hitters who chase upstairs. That patchwork can work—if the command is there. Walks are the red flag.
For the Astros, the priorities are clearer: protect the compromised staff, get the ball to the late innings clean, and avoid overusing the same reliever on back-to-back days. With Arrighetti and Sousa down, the margin for error shrinks if a starter exits early. Expect more quick mound visits and an emphasis on first-pitch strikes to stay out of ambush counts.
Minute Maid Park itself shapes tactics. The roof and dimensions reward line drives and punish hanging breaking balls. Outfield positioning and relay throws matter as much as exit velocity this weekend. Both clubs will want ground balls with men on; airborne mistakes can turn into three-run snapshots.
Analytics hint at how this plays out for Atlanta. Take away Smith-Shawver’s and Schwellenbach’s bat-missing ability, and you get fewer strikeouts and more balls in play. That shifts stress onto infield range and positioning. The Braves’ staff can still survive by living on the edges, but long innings raise the pitch counts that force early hooks and expose a thin bullpen.
The calendar adds another layer. With Hernández’s IL move backdated to September 9, the earliest he can return lands after this series. Most of Atlanta’s other injuries are either long-term or without near-term timelines, so there’s no cavalry coming by Saturday night. The group you see is the group that has to get 81 outs.
There’s also the human side. Veterans like Murphy and Riley set tone and routine. Without them, younger players take bigger bites: late-inning at-bats against premium velocity, tricky reads at third, and mound visits in traffic. These are real evaluation moments. The Braves can test who handles noise, who adjusts mid-game, and who can carry an assignment two days in a row without a dip.
Matchup pockets to watch: for Atlanta, any sixth-inning spot with a left-handed Astro at the plate and men on base, the precise place Bummer would usually enter. For Houston, see how they navigate the heart of the Braves’ order without fearing Riley’s damage on mistakes. If the Astros pump strikes early, Atlanta may counter by hunting first-pitch fastballs—contact quality will decide if that’s payoff or pop-out.
Keep an eye on three tells each night: early pitch counts for the starters, velocity bands for mid-game relievers (any sudden dip signals fatigue), and how catchers handle two-strike waste pitches with runners aboard. One passed ball or one missed backdoor call can swing a low-scoring game under these conditions.
Zooming out, the stakes differ but are real for both dugouts. The Braves are already out, but this is audition season. Roster spots, roles for spring, arbitration decisions—those are in play. For the Astros, health management and leverage planning are the priorities in mid-September baseball. Every clean inning banks rest. Every soft-contact out buys a matchup later.
So, no, this isn’t the star-driven series some expected back in April. Instead, it’s something more subtle: three nights of problem-solving. The side that guesses right on matchups, keeps the ball in the yard, and squeezes 27 outs from a stretched staff will leave the weekend feeling a little healthier, even if the injured list says otherwise.